1. Field of the Invention
The present invention relates to an anti-adhesion agent composition for asphalt, the anti-adhesion agent composition having excellent sprayability and a high anti-adhesion property for asphalt, persistently providing such an anti-adhesion effect, and having excellent storage stability.
2. Description of the Related Art
An asphalt mixture in which asphalt and aggregate have been mixed together is used to pave roads. Such an asphalt mixture is loaded onto the bed of a truck in an asphalt mixture plant and carried to a work site on a road. In the loading of an asphalt mixture onto the bed of a truck, since the asphalt mixture has a high temperature of about 200° C., the asphalt mixture adheres to the bed made of metal and a portion of the asphalt mixture cannot be used for the performance of work. Furthermore, in asphalt mixture plants, asphalt mixtures adhere to mixers, hoppers, and conveyor belts, which is also problematic.
Accordingly, to suppress adhesion of asphalt mixtures, diesel oil has been sprayed onto the beds of trucks and diesel oil has been periodically sprayed onto mixers, hoppers, and conveyor belts with spraying apparatuses installed therein. However, since diesel oil dissolves asphalt, such methods cause a problem in that the quality of asphalt mixtures is degraded. To solve the above-described problems, there is an asphalt anti-adhesion agent in which an ester oil or a nonionic surfactant that is less miscible with asphalt mixtures is turned into an emulsion (International Publication WO03/035809). However, since this agent is an emulsion and separates over time, stirring of the agent is required whenever it is used. Furthermore, when the agent is diluted in order to be sprayed and the diluted solution is stored in an outdoor tank, the diluted solution solidifies at low temperature in winter. Thus, the agent has a problem in terms of storage stability. There is also an asphalt anti-adhesion agent using a polyhydric alcohol (Japanese Unexamined Patent Application Publication No. 2006-241409). However, such an agent composed of only a polyhydric alcohol does not spread sufficiently over metal surfaces and hence does not provide a sufficiently high anti-adhesion property for asphalt. There is also an asphalt anti-adhesion agent using a polyhydric alcohol, polyvinyl alcohol, a polyalkyl glycol, and derivatives of the polyalkyl glycol (U.S. Pat. No. 6,486,249). However, use of such a combination of polyvinyl alcohol, a polyalkyl glycol, and derivatives of the polyalkyl glycol does not provide a sufficiently high spreadability over metal surfaces for the agent. Thus, such an agent does not have excellent sprayability and does not provide a sufficiently high anti-adhesion property for asphalt.